Lubricant recovery device in sewing machines

ABSTRACT

A lubricant recovery device for the needle bar of a sewing machine including a combined wiping and guide element for removing excess lubricant from the needle bar and directing it into a suitable receptacle from which it is drawn and transferred to a pumping apparatus adopted to recycle the lubricant.

United States Patent Marforio Nov. 20, 1973 [5 LUBRICANT RECOVERY DEVICE IN 2,381,685 8 1945 Parry 112 256 SEWNG MACHINES 2,697,995 12/1954 Nic01ay.... 112/256 1 2,627,830 2 1953 Ritter 112/256 Inventor: Ncrlnc Mnrfcrlc, Mllan, Italy 2,619,061 11/1952 Ritter e161 112/256 [2 Filed: y 1972 FOREIGN PATENTS 0R APPLICATIONS 21 Appl, N 254,112 689,672 4 1953 Great Britain 112 256 Primary Examiner-Geo. V. Larkin [30] Forelgn Apphcatlon Pnonty Dam AttorneyJohn R. Bronaugh et a1.

June 15, 1971 Italy 25838 A/7l 52 U.S. c1. 112/256 [57] ABSTRACT [51] Int. Cl. 11051 71/00 A lubricant recovery device for thc nccdlc bar of a [58] Field of Search 112/256; 184/5, 6, sewing machine including a combined wiping and 184/100 guide element for removing excess lubricant from the needle bar and directing it into a suitable receptacle [56] References Cit d from which it is drawn and transferred to a pumping UNITED STATES PATENTS apparatus adopted to recycle the lubricant. 3,663,071 5 1972 Kates 184/5 x 9 Claims, 5 Drawing Figures p I I l E [1 'I 11 \1 "I Ml {1 1 1 [I 1 l 1 1 F L l t l I LUBRICANT RECOVERY DEVICE IN SEWING MACHINES BACKGROUND OF THE INVENTION In sewing machines and especially models of the industrial type which are caused to function at high speed and for extended periods of time it is necessary that a sufficient amount of lubricant be supplied to the needle bar which in a well known manner is driven and caused to reciprocate very rapidly in a generally verticaldirection.

Needle bars are commonly supported for reciprocating movement in aligned bushing members carried in the head portion of a sewing machine.

For the desired and expected operational performance of a sewing machine and to meet with the efficiency expectations thereof, the needle bar must be capable of reciprocating freely and unrestricted and at a very high rate. To accomplish this, clearance must be provided between the needle bar and the inside diameter of its respective guiding bushings.

It is quite obvious that machines operating at high speed require a greater flow of lubricant by comparison than those operating at a lesser speed and for shorter intervals of time.

A well known problem which exists when providing a sufficient flow of lubricant to the moving parts of high speed sewing machines is that of loss of lubricant from said machines.

A particularly troublesome location in sewing machines for the loss of lubricant is that area of the lowermost bushing member utilized for guiding the needle bar during its reciprocating movement. The lubricant which leaves the machine in this area inevitably drops onto the fabric being worked on, causingquite obvious damaging results thereto.

The cause of loss of lubricant in this area can be attributed to the preferred operating clearence between the needle bar and its guiding bushing member carried in the head portion of the machine. This problem would not be completely corrected by providing lessr clearance, or in other words, maintaining a closer tolerance between the needle bar and its respective guiding bushing members. 7

The adoption of a supplementary sealing means would not be the answer to this problem for loss of unrestricted movement of the needle bar would create a diminution in the efficiency of the machine, as well as construction difficulties.

The lubricant recovery device of the present invention permits the desired and required amount of lubricant to be distributed to the various moving parts of a sewing machine and at the same time prevents loss of the lubricant in the troublesome area described above.

SUMMARY OF THE INVENTION The present invention provides a device for the recovery and recycling of the lubricant directed to the bushing members adopted to guide the needle bar during its reciprocating movement.

The lowermost bushing carried in the head portion of the machine which serves to guide the needle bar during its intended function includes a necked lower end to which attaches a cylindrical ring-like lubricant rolling cup. I

The lower end of this bushing is provided with a truncated recess that communicates with the bore of said bushing within which the needle bar is caused to slide. The upper end of this truncated recess communicates with a radial recess within the bushings bore and serves to accumulate excess lubricant as the needle bar is reciprocated. The lower end of the truncated recess is disposed in close proximity with the internal portion of the lubricant collecting cup and the configuration of said recess provides a means which allows the excess lubricant to flow into said cup.

From the collecting cup the lubricant is caused to flow to a suction duct that directs it to a pumping apparatus which is effective in recycling said lubricant.

It is a general object of the invention to provide an improved means for controlling the lubricant directed to the needle bar of a sewing machine while maintaining the lubricating requirements therefor unchanged.

A further object of the invention is to provide a device for the recovery of the lubricant normally lost during lubrication of the needle bar.

A further and more specific object of the invention is to provide a means for recycling the lubricant recovered from the reciprocating needle bar.

These and other objects of the invention will become more fully apparent by reference to the appended claims and as the following detailed description proceeds in reference to the figures of drawing wherein:

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a view in front elevation and partially in section of a sewing machine showing the lubricant recovery device according to the invention applied thereto;

FIG. 2 is a sectional view of a portion of FIG. 1 on an enlarged scale showing further detail of the lubricant recovery device;

FIG. 3 is a perspective view in exploded form showing the device according to the invention;

FIG. 4 is a sectional view of the lower needle bar guide bushing as seen looking in the direction of the indicating arrows of line AA in FIG. 2, and FIG. 5 is a view in side elevation of the ductlines and associated fitting for returning the recovered lubricant to the pumping apparatus for recycling.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a sewing machine to which the present invention is applicable is shown and includes among its many parts a base 1, a standard 2 having an arm 3 extending laterally therefrom which includes a depending portion at the unsupported end thereof.

Above the base 1 and immediately adjacent to the standard 3 a fiat planar surface defining a work table 4 is provided and extends in a direction to underlie the depending portion of arm 3.

The sewing machine, hereinafter referred to as machine, is driven by an electric motor (not shown) which is connected by means of a driving belt 5 with a pulley 6 that is fixed on the main shaft 7 of said machine.

The main shaft 7 is joumaled with the base 1 and has formed thereon a crank 9 with the lower end of an upwardly directed connecting rod 8 operatively connected thereto. The upper end of rod 8 is attached to an arm 13 that is fixed to and extends from a horizontally disposed shaft 10 carried within the arm 3. Shaft 10 is journalled for oscillatory movement by a pair of aligned and spaced bushing members 14 which are fixed within the arm 3 of the machine (FIG. 1).

Rod 8 by means of its connections between shaft 7 and shaft 10 effects oscillatory movement of the latter which is adapted to reciprocate a needle bar 11, carrying the usual needle 12, in a generally vertical direction. Vertical reciprocation of the needle bar 11 is made possible through its connection to shaft 10 which includes a laterally extending fork-like element 15 (partially shown in FIG. 1) between the arms of which the needle bar 11 is keyed in a central point. This forklike element 15 is disposed on that end of shaft 10 opposite to that end at which arm 13 is fixed.

The needle bar 11 is caused to reciprocate vertically in two aligned guide bushings 16 (one only shown) which are fixed in spaced relation within the unsupported end of the arm 3 (FIG. 1).

The device of the present invention for the recovery of the lubricant normally lost as a result of it passing through the clearance existing between the needle bar 11 and the bushing 16, includes a scraper or wiper which is represented by a radial recess 17 disposed within and adjacent to lower end of said bushing.

The device also includes a guide means for the lubricant collected by the wiper and is formed by a substantially truncated cone-like recess 18 with its upper and communicating with the radial recess 17 and its lower with the lower end of the bushing 16. With the recess 18 being truncated or bell shaped the surface thereof extends downwardly and outwardly and the excess lubricant collected by the radial recess 17 when the needle bar 11 rises will adhere to the bell shaped wall and flow downwardly toward the lower end of the bushing 16.

It should be understood that the bell shape of the recess 18 need not terminate at the lower end of the bushing 16 and that other configurations could be utilized, such as being bell shaped for a portion of its length and becoming cylindrical adjacent the lower end of said bushing 16.

In the preferred embodiment, the lower end of the bushing 16 and its recess 18 are disposed so as to communicate with a collecting element for the lubricant which is in the form of a ring cup generally indicated by numeral 19 (FIGS. 2 and 3).

This ring cup 19 includes an annular lower surface 190, an inner upwardly directed cylindrical wall 19c and an outer upwardly directed cylindrical wall 19b. The outer cylindrical wall 19b of the ring cup extends upwardly a greater distance than the inner cylindrical wall 190. I

As shown in FIG. 2, the lower end of bushing 16 is provided with a necked portion 20 which provides a means for the assembly of the ring cup 19 on this end of said bushing. The length of the outer upwardly directed cylindrical wall 19b of the ring cup 19 is greater than the length of the necked portion 20 on the bushing 16 and when in assembled position does not permit the lower end of said bushing to make contact with the annular lower surface 19a of said ring cup. The ring cup 19 has a centrally disposed hole and the diameter d thereof is greater than the diameter D of the needle bar 11 (FIG. 2) and serves to avoid interference between the reciprocating needle bar 11 and said ring cup. In assembled position, the annular lower surface 19a of the ring cup 19 is disposed directly below recess 18 in the bushing 16 and is adapted to receive theexcess lubricant flowing downwardly along the bell shaped surface of said recess.

The invention also includes a means for removing the excess lubricant from the bell cup 19 through a suction duct 21 which directs it to a means whereby said lubricant is recycled. The means for removing the lubricant from the ring cup further includes a duct 22 formed within the side wall of the bushing 16 and extending in a direction parallel with the axis of said bushing. This duct 22 extends to the lower end of the bushing 16 and communicates with the lubricant that accumulates in the ring cup. In operative cooperation with the upper end of the duct 22 there is provided an anti-siphon trap 23 that serves to prevent the reflow of the lubricant back to the ring cup should suction in the duct 21 fail to occur. The anti-siphon trap 23 is of the well known inverted U-shaped duct configuration. As shown in FIG. 2 a decending branch of the anti-siphon trap 23 is formed by the combination of a recess 24 in the outer surface of the bushing and the wall of the seat for said bushing that is formed in arm 3.

A duct 25 which extends in a substantially horizontal direction and formed within the arm 3 of the machine interconnects the anti-siphon trap 23 with a so-called sump 26.

The excess lubricant drawn from the ring cup 19 is directed through duct 25 and into the sump 26 from which it is drawn by the suction duct 21 that is connected to said sump by means of a fitting 27.

As shown in FIG. 2 numeral 28 identifies another suction duct which communicates with another sump 29 that serves to collect the excess lubricant flowing downwardly from'the walls of and components disposed within the arm 3. It should be noted that sumps such as those identified by numeral 29 are well known in the art and are usually provided in sewing machines for the purpose of recycling the lubricant.

In FIG. 1 the suction ducts 21 and 28 are shown located within the support housing or head portion of the machine and are directed to a lubricant pump 30 which is of the conventional gear type and well known. Both suction ducts 21 and 28 merge into a single duct 31 (FIG. 5) at their point of attachment to the lubricant pump 30. The inside diameter of duct 31 is slightly smaller than that of duct 28, but greater than that of duct 21. This differential in duct size serves to increase the lubricant flow rates within each duct when it is drawn through the ducts by means of the vacuum created by the pump 30.

Although the present invention has been described in connection with a preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art will readily understand. Such modifications and variations are considered to be within the perview and scope of the invention and the appended claims.

I claim:

1. In combination with a sewing machine of the type having a support housing with guide members carried thereby for supporting a needle carrying needle bar for reciprocating movement in a generally vertical direction, a lubricant recovery device operatively associated with the needle bar comprising a guiding bushing within which the needle bar is caused to slide during its reciprocating movement, wiping means for removing lubricant on the needle bar as it moves in said guiding bushing, guide means operatively associated with said wiping means for directing the lubricant away from the latter, a collection element for receiving the lubricant from said guide means, flow means for removing the lubricant from said collection element and means associated with said flow means for recycling the lubricant.

2. The mechanism according to claim 1 wherein said lubricant recovery device further includes an antisiphon trap to prevent return of the lubricant to said collection element.

3. The mechanism according to claim 1 wherein said wiping means defines a radial recess formed within and adjacent one end of said guiding bushing.

4. The mechanism according to claim 3 wherein said guide means defines a truncated recess communicating with the lower end of said guiding bushing.

5. The mechanism according to claim 4 wherein said collection element defines a ring cup assembled on the lower end of said guiding bushing.

6. The mechanism according to claim 5 wherein said ring cup includes an inner cylinder wall and an outer cylindrical wall for attaching said ring cup to said guiding bushing. Y 1

7. The mechanism according to claim 6 wherein said recycling means comprises a pump member operatively associated with said flow means.

8. The mechanism according to claim 7 wherein said flow means defines duct members for directing the lubricant to said pump member.

9. The lubricant recovery device according to claim 8 wherein the lubricant is drawn by suction means through said ducts by means of a vacuum created by said pump.

UNITED S TATES' PATENT OFFICE" CERTIFICATE OF CORRECTION Patent No. 3,773,003 Dated November 3 Inventofls) Nerino Marforio It is certified that error appears in the'above-idntifid patent and that said Letters Patent are hereby corrected as shown below:

' Onthe cover sheet insert H [73] Assignee: SpA Virginio Rimoldi a ,c., Mila nr-Italy,

a corporation of Italy j Signed and sealed this 24th day of-- Septe n'iber" 1974.

(SEAL) Attestz v I v I I McCoy GIBSON CQMARS 'HALLfD NN Attesting Officer ommissioner of Patents 

1. In combination with a sewing machine of the type having a support housing with guide members carried thereby for supporting a needle carrying needle bar for reciprocating movement in a generally vertical direction, a lubricant recovery device operatively associated with the needle bar comprising a guiding bushing within which the needle bar is caused to slide during its reciprocating movement, wiping means for removing lubricant on the needle bar as it moves in said guiding bushing, guide means operatively associated with said wiping means for directing the lubricant away from the latter, a collection element for receiving the lubricant from said guide means, flow means for removing the lubricant from said collection element and means associated with said flow means for recycling the lubricant.
 2. The mechanism according to claim 1 wherein said lubricant recovery device further includes an anti-siphon trap to prevent return of the lubricant to said collection element.
 3. The mechanism according to claim 1 wherein said wiping means defines a radial recess formed within and adjacent one end of said guiding bushing.
 4. The mechanism according to claim 3 wherein said guide means defines a truncated recess communicating with the lower end of said guiding bushing.
 5. The mechanism according to claim 4 wherein said collection element defines a ring cup assembled on the lower end of said guiding bushing.
 6. The mechanism according to claim 5 wherein said ring cup includes an inner cylinder wall and an outer cylindrical wall for attaching said ring cup to said guiding bushing.
 7. The mechanism according to claim 6 wherein said recycling means comprises a pump member operatively associated with said flow means.
 8. The mechanism according to claim 7 wherein said flow means defines duct members for directing the lubricant to said pump member.
 9. The lubricant recovery device according to claim 8 wherein the lubricant is drawn by suction means through said ducts by means of a vacuum created by said pump. 